Axons derived from myelinated axons and isolated as myelin-free entities will be isolated from bovine and rat CNS. The protein and lipid composition of the axonal preparations will be determined. Particular emphasis will be placed on the axonal sphingolipids cerebroside and sulfatide as they relate to the myelin sheath. The metabolic capabilities of the axonal preparations for the synthesis and degradation of these sphingolipids will be evaluated. A procedure will be developed to isolate the axolemma of bovine axons. The proteins and lipids of the isolated axolemma will be determined. Characterization of the RNA found in bovine axons will also be carried out. Finally in vivo studies will be performed in the rat to evaluate the relationship between the axonal and myelin sphingolipids.